Pentaerythritol Phosphate Melamine Salt, A New Aggregating Reagent for Oilfield Chemical Sand Control: Preparation, Properties, and Mechanism

Abstract

The production of sands in oil well production has long been a crucial and thorny issue, but many related technologies are either costly or ineffective. This study introduced a new aggregating reagent, pentaerythritol phosphate melamine salt (PPMS for short), for controlling this problem. PPMS was the reaction product of pentaerythritol, phosphoric acid, and melamine, and there was an amine and a phosphate ester (both are positively charged) in its chemical structure. It could effectively change the ζ potentials of solid particles and help them aggregate through hydrogen bonds and electrostatic interactions, thereby aggregated particles could settle down at the bottom of the pore holes without severe formation permeability damage, which plays a remarkable role in eliminating the co-production of formation particles with oil. PPMS exhibited an excellent performance when the concentration was 0.8 wt % under 60 °C at a neutral environment, at which PPMS (positively charged) not only can highly condense the double layer electric field but also can better react with clay particles (negatively charged) through adsorption and charge neutralization; thus the negative charge of clay surface could decrease to the minimum (almost 0 mV). At the same time, PPMS might have the potential to enhance oil recovery.

Functionalized multiwalled carbon nanotubes with monocomponent intumescent flame retardant for reducing the flammability and smoke emission characteristics of epoxy resins

“…This result indicates that the CNTs have C─OH groups that provide the ability to graft PPMS on the surface of CNTs. When CNTs were grafted with PPMS, the intensities of peaks corresponding to P─O─CH 2 ─C groups at 868 cm −1 and P─O─C groups at 1031 cm −1 are increased with introduction of CNTs . In addition, the major characteristic peaks in both CNT‐OH and PPMS are found in PPMS‐CNT, indicating that PPMS was successfully grafted on the surface of CNTs, as shown in Figure .…”

A comprehensive research in chemical consolidator/stabilizer agents on sand production control

“…Table 1 summarizes the clay specifications. Talaghat et al (2009) used sandstone core composed of quartz, dolomite, calcite and clay, Liu et al (2016) used bentonite clay with a medium particle size of 5.1 µm, Hafez et al (2011) used silicate sand with particle size distribution of 150-250 µm, Mishra and Ojha (2016a) used sandstone core, and Li et al (2017) used quartz with mesh size ranges between 40 and 120 mesh and kaolinites, as sand to investigate sand production control. From previous works on sand control and chemical analysis of formation sand, elements that may be found on sand production and need to be consolidated/stabilized are summarized in Table 2.…”

“…More than ten tests have been applied for evaluating the consolidation/stabilization qualities of consolidators/stabilizers in the reviewed articles. The applied methods are zeta potential (Liu et al 2016), particle size distribution (Liu et al 2016), sand column (Liu et al 2016), flow test (Liu et al 2016), porosity reduction (Bahmani 2017), permeability damage (Bahmani 2017), unconfined compressive strength (Talaghat et al 2009), shear strength (Liu et al 2011), penetration resistance (Shulga et al 2001, flow erosion resistance (Liu et al 2011), and rainfall erosion resistance (Liu et al 2011). Initial seven experimental tests mentioned above are usually performed in sand production control (oil and gas industry), lasts five tests are applied in the field of desertification, dust control, etc.…”

“…Poorly consolidated reservoirs contain near 70.0 percent of the world's hydrocarbons (Talaghat et al 2009), hence many oil and gas fields are subjected to sand production. Reports of the volumetric concentration of sand particles in oil pipe systems range from 1.0 to 40.0% (Liu et al 2016). A high concentration of sand in the production fluids of oil and gas wells could result in operational problems such as erosion of pipes and separators, instability of production cavities, and loss of well control (Talaghat et al 2009).…”

“…A high concentration of sand in the production fluids of oil and gas wells could result in operational problems such as erosion of pipes and separators, instability of production cavities, and loss of well control (Talaghat et al 2009). The high cost of sand production controlling technology caused a missing of several hundred millions of dollars, yearly (Liu et al 2016).…”